WHAT WILL JUSTIFY HUMAN EXPANSION INTO SPACE?

Artist concept courtesy of NASA

Artist concept courtesy of NASA

I’d be willing to bet that the great majority of science fiction stories set in the future include a significant human presence in outer space as a given, even if the stories themselves aren’t about space. Space travel is just a huge part of the SF imagination. Human colonies on the Moon, Mars, moons of the gas giants, and at least some asteroids. Regular traffic to and from Earth, with established shipping routes weaving through the solar system for passengers and cargo. Maybe huge colony ships or faster-than-light spacecraft charging their way toward other suns.

But why do we seem so sure that will happen? Just because it would be cool?

That isn’t the way the human world works. To be frank, the forces that drive human exploration and expansion are usually necessity and greed. We go to new places because there isn’t enough room at home (or resources, or peace and prosperity) or because somebody stands to make a lot of money. But what about going beyond our own planet?

I’ve discussed the economics of space mining before. In these days when private enterprise is getting into the space launch business, companies like SpaceX and Orbital Science still need $27,000 to $43,000 to take a pound of cargo and put it into orbit. Even in the space shuttle days (because it could carry much more cargo) the price per pound was about $10,000. Now imagine the amount of steel and other heavy stuff needed to build a big transportation hub and/or warehouse complex in orbit. Or the weight of construction equipment needed to be hauled to the Moon to dig mines. Or even just the fuel to power the equipment and spacecraft. Water is about the cheapest fuel around (broken into hydrogen and oxygen), but it’s still heavy (that half-litre bottle you like to drink weighs more than a pound).

It’s true that the first three hundred kilometers of the journey from Earth are by far the most costly, so there have been proposals to replace rocket boosters with magnetically-levitating launch tracks, or a space elevator with cables made of nanomaterials hung from giant stations in geostationary orbit. There are lots of creative launch alternatives, but such things would cost billions, if not trillions of dollars to build. And all of that is just to create the infrastructure that mining and shipping operations would require.

What end product could possibly be worth such an investment? Even if speculations are true that some asteroids might contain as much platinum and related metals as have ever been mined on Earth (only an estimated 16 tons), with a price this week of around $950 per ounce that still only amounts to about $480 million. It would take a lot of asteroids for investors to make their money back, and that’s assuming the demand and price for platinum metals would stay high (which it wouldn’t with such large amounts dumped onto the market).

Some will say that there’s huge value in research and certain kinds of chemical processing that can only be carried out in zero gravity. That may very well be true, but such operations would be best placed in Earth orbit, close to the consumer market—there would be no need to colonize other planets for them.

All in all, I’m of the opinion that, at least until the Earth completely runs out of the mineral resources we need (including recycled materials), space mining with Earth as its main market won’t be the driver that creates a system of colonies and industries throughout the solar system. But I used italics because, if we create colonies on other planets and moons for some other reason, then space mining will be much more viable to supply those outposts than having to ship material from Earth.

So my point is that, if a widespread human presence in space beyond the Earth is ever to happen, it will be for reasons other than profit.

“Running out of room at home” could be one such reason—we don’t yet have our population growth under control, and rising living standards are creating a demand for food and other goods that may be beyond our beleaguered planet’s ability to supply for much longer. But as science fiction buffs, we can speculate about others:

- pollution, climate change, or nuclear war makes the planet unliveable.

- runaway products of genetic engineering or nano-engineering make the planet unliveable.

- a cosmic catastrophe like an asteroid strike, solar flare-up, or magnetic field disruption makes the planet unliveable.

- the Earth is about to be swallowed by a black hole (and would therefore be unliveable!)

Or possibly if the uber-wealthy 1% and the exploited 99% just can’t live together on the same planet any longer.

There are happier possibilities too:

- if a very inexpensive gravity-controlling technology were developed (especially in combination with force-field shields against radiation). Spacecraft might be less costly than submarines.

- if a faster-than-light spaceship drive were invented. We’d have a much greater incentive to explore other star systems (spared hundreds of years of travel time).

- if life is discovered on other planets or moons. We’d feel compelled to investigate it and possibly even protect and nurture it long-term.

- if research discovered that living in space or on other worlds provided a significant benefit to human health and lifespan.

-if genetic engineering made humans able to thrive under the harsher conditions elsewhere in the solar system (lower gravity, higher radiation, different atmospheres and temperatures).

Or if an advanced alien race were to make its presence known to us—whether in peace or in conflict—we’d have a strong impetus to establish a firm foothold in space.

Will there ever be humans living and working all over the solar system and beyond? I think so. Eventually. But it’ll take a very compelling motivation—maybe many compelling motivations—to make it happen. For once, the lust for money won’t be enough.

TIME FOR ANOTHER LOOK AT TIME?

A recent release from the University of British Columbia, Canada, inspired me to make the time to revisit the always timely subject of time travel (OK, maybe I should travel back in time and redo that sentence….)

Ben Tippett, a mathematics and physics instructor at UBC’s Okanagan campus, specializes in Einstein’s theory of general relativity and has come up with the mathematics to show that time travel should be possible. I’ll spare you my attempt to explain it mathematically (neither of us has that much time) but you’ve probably heard space described as being like a giant trampoline: it’s fairly flat in most places, but if you place something big and heavy on it (like a bowling ball, or a planet) you’ll make a deep depression in the fabric, and things nearby will roll down the side of the depression toward the object at the bottom. That’s a visualization of the force of gravity which, Einstein says, creates curves like that in space. UBC’s Tippett says that high gravity bends time as well as space, citing evidence that time passes more slowly close to a black hole, for instance. Bend time enough, and you can curve it into a loop that could be travelled backward or forward. (Technically, physicists call it a “closed time-like curve”.) At least, that’s what Tippett’s mathematical model shows. How it could be done is a whole other story—as he’s quick to point out, it would require exotic substances that don’t currently exist.

Still, I’m happy about any evidence that doesn’t rule out the possibility of time travel (I also like that Tippet named his model a Traversable Acausal Retrograde Domain in Space-time (TARDIS), which all Dr. Who fans will appreciate).

Actual hypotheses about how time travel would have to be accomplished include things like infinitely long cylinders spinning at a few billion revolutions per minute with ten times the mass of the sun, or donut-shaped areas of vacuum surrounded by hugely powerful and precisely focused gravitational fields (and that one also has a limitation that you couldn’t travel to a time before the machine was created.) Even Elon Musk won’t be bankrolling projects like that any time soon.

So should science fiction writers just drop the whole idea of time travel?

Not on your life (or infinitely recurring lifetimes, either).

H.G Wells didn’t try to explain the science when he wrote The Time Machine, and if it’s good enough for Herb it’s good enough for us. Like most of the best science fiction, the novel was a commentary on Wells’ own time, especially socialism and the British class system. It’s also wonderfully creepy. Better to leave out the dreary (and probably wrong) explanation of how the thing works, and focus on the story: the myriad ways time travel might be used—and mess things up!

A whole sub-genre of time travel stories involves characters messing with history, including one of my favourites, A Sound of Thunder by Ray Bradbury, in which the squashing of a butterfly changes the future. Another sub-genre professes to follow the credo that time travel is impossible, so instead the characters travel to a different time in an alternate universe. Michael Crichton’s Timeline is one of those, allowing the protagonists to have lots of adventures in the past, and even stay there, without screwing up our timeline (the title notwithstanding). Apparently it’s OK to screw up somebody else’s universe!

Robert J. Sawyer played a different trick with time in the novel Flashforward in which everyone on Earth gets a glimpse of their lives twenty-one years in the future (but doesn’t actually travel there). A host of personal dilemmas ensues. Sawyer also does something tricky with time travel in his novel Starplex—he avoids having to explain the technology by making it an exclusive ability of beings from billions of years in the future. Michael Swanwick’s Bones of the Earth does something similar, offering time travel as a gift from beings of the extremely far future to near-present-day humans, under very strict conditions. It’s a neat dodge—you don’t have to justify or explain time travel, you just have to believe that humans will someday figure it out.

All I can say is: if you’re reading this in the year 2 Billion AD, come back and visit me. We’ll talk.